Electric-arc lamp.



No. 781,937. PATENTED FEB. 7, 1905. A. G. DAVIS & J. B. HUBBELL.

ELECTRIC ARC LAMP.

APPLICATION rum) JULY 7, 1904 bell,

. Inventors: JIlbert G. Davis,

John E. I-I?b y l 4 8 P 6 N J 1v 9!. l J 34 O M 8 !||.-|rr E 3 x 4 .Q P.

n ll Witnesses.

UNITED STATES Patented February '7, 1905.

PATENT OEEIcE.

ALBERT Gr. DAVIS AND JOHN E. HUBBELL, OF SGHENEG'UADY, NEIV YORK,ASSIGNORS TO GENERAL ELECTRIC COMPANY, A CORPO- RATION OF NEW YORK.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 781,937, dated February'7, 1905.

Application filed July 7,1904. Serial No. 215,569.

T0 rtZl whom, it may concern.-

Be it known that we, ALBERT Gr. DAVIS and JOHN E. HUEBELL, citizens ofthe United States, residing at Schenectady, county of Schenectady, Stateof New York, have invented certain new and useful Improvements inArc-Lamps, of which the following is a specification.

hen electrodes for arc-lamps are constructed out of many materials whichmay be advantageously employed for the purpose, there is a tendency tothe formation on one or both of the electrodes of the lamp of a film,layer, or coating of material which is a nonconductor or poor conductorof electricity, at least when cold.

Our present invention has for its purpose the provision of suitablemeans for preventing this layer or film of material from injuriouslyaffecting the operation of the. lamp in which the electrodes areemployed.

In carrying out our invention we have provided means for puncturing thenon-conducting film or layer and penetrating through to the goodconducting material forming the body of the electrode.

It has been heretofore discovered that with suitable negative electrodesgiving a flaming or luminous are positive metallic non-consumingelectrodes may advantageously be employed. In the present application wehave shown our invention embodied in an arc-lamp employing anon-consuming positive electrode, though our invention in all of itsaspects is not limited to use with such an electrode or, indeed, to usewith any particular form of lamp mechanism.

The various features of novelty which characterize our invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding, however, of ourinvention reference maybe had to the accompanying drawings anddescription, in which we have illustrated and described embodiments ofour invention.

Of the drawings, Figure 1 is a view, partly in elevation and partly indiagram, showing one embodiment of our invention. Fig. 2 is a similarview, with parts in section, showing a different form of our invention.Fig. 3 is a view, partly in section with parts broken away, taken atright angles to Fig. 1, showing a portion only of the mechanism shown inFig. 1; and Fig. A shows another form of puncturing device.

Referring to the construction shown in Figs. 1 and 3, the mechanismthere shown is substantially like that shown in an application forLetters Patent on improvements in arclamps, Serial No. 181,332, filedjointly by Richard Fleming and Cromwell A. B. Halvorson, Jr., November16, 1903, except as the same has been modified by the addition of ourpresent invention. In this construction 1 represents-a platform, fromthe under side of which extends a tubular member 2, formed, preferably,of some metal, such as copper, which is a good conductor both of heatand electricity. A pair of bowed members 3have clamped between theirends the ends of the positive electrode of the lamp, which is in theform'of an arc-shaped bar 4, made of some material, such aswrought-copper, which is a good conductor both of heat and electricity.The bowed members 3 are pivoted to the member 2 to turn about an axisextending transversely to the axis of the member 2. Slots are formed inthe wall of the mcmberQ, through which the bar 4. passes. A puncturingdevice or member 5 is carried by the bar at at one side of its center.The member 5 may be formed of some material like musketsteel, which whenheated is tempered by cool ing slowly in air, orof other suitablematerial. The member 5 may be removably secured to the bar A bydovctailing, as shown. Preferably a driving lit between the tenon of themember 5 and the walls of the slot in the bar 4 is employed. A sharpenedprojection 5 extends from the member 5. \V hen the bar :h is in theposition shown in Fig. 3, the projection 5 is in line with the axis ofthe member 2. A projection 6 from one of the bowed members 3 ispivotally connected by links 7 to a U-shaped armature 8, located abovethe platform 1. To the under side of the U-shaped armature 8 is securedone member 9 ofa dashpot. The other member 10 of the dash-pot is carriedby the platform 1. The dash-pot employed is arranged to prevent a rapiddownward movement of the armature 8 without retarding its upwardmovement. The apcrtured end of the pawl member 11 of a clutch 12 isloosely sleeved to the stem 9, connecting the armature 8 and dash-potmember 9. The yoke of the clutch 12 surrounds a tubular member 13, whichslides upon a post 14. The post 14 is secured at its upper end to across-head 15, supported by a post 16, which is carried by the platform1 and extends par. allel to the post 14. The lower end of the tubularmember 13 carries an arm 17, which in turn holds the negative consumingelectrode 18 of the lamp in line with the axis of the tubular member 2.A guide carried by the member 13 engages the post 16 to prevent angulardisplacement of the member 13. The yoke member of a clutch 19 surroundsthe member 13 below the clutch 12. The pawl 20 of the clutch 19 isformed with an enlarged opening in it, through which the post 16 passes,the post serving as a guide to prevent angular movement of the clutch19. The movement of the pawl 20 is limited by stops 21 and 22, carriedby the post 16 above and below the pawl 20, respectively. A projectionfrom the stop 21 forms a rest for the yoke member of the clutch 12 whenthe mechanism is in the position shown in Fig. 1. A helical spring 23,one end of which is secured to a bracket and the other end to the freeend of the pawl 20, forms a means for normally holding the pawl in theposition in which it locks the clutch 19 to the member 13.

Current is supplied to the lamp at the terminals and 31. The terminal31, which is the negative terminal of the lamp, is connected to theelectrode 18 by conductor 32. A conductor 33 leads from the terminal 30to one terminal of the winding of a cut-out 34.

, The other terminal of the winding of the cutout 34 is connected,through a screw 35 and conductor 36 and members 3, to the are-shaped bar4, which forms the positive electrode of the lamp. \Vith the lamp asactually constructed connection is ordinarily made directly to the wallsof the member 2 and the bowed members 3 are connected to the member 2 bya flexible conductor 37, as shown in Fig. 3. The cut-out member 34 isprovided with a pivoted armature 38, carrying a contact 39. \/V hen thewinding of the cut-out 34 is not operatively energized, the contact 39is in engagement with the contact 40. hen, however, the winding of thecut-out 34 is operatively energized, the armature 38 is tilted and theconductors 39 and 40 are separated.

A conductor 41 connects the terminal 30 to regulating"resistance 42. Thecontact 39 is connected by conductor 43 with one terminal of the winding44, which cooperates with the U-shaped armature 8. The other terminal ofthe winding 44 is connected to the terminal 31. One terminal of thepotential coil 45 is connected to the conductor 41 by a conductor Theother terminal of the potential coil 45 is connected to the conductor 43by a conductor 47. The core of the potential coil 45 carries aninsulated contact member 48. The movable armature of the potential coilcarries an insulated contact 49. The contact member 49 is connected withthe conductor 33 by a conductor 50. A conductor 51 connects the contactmember 48 to the lower terminal of the cut-out member 34.

The out-of-service condition of the lamp mechanism is shown in Fig. 1.On connecting the terminals 30 and 31 to a suitable source current willbegin to flow from the terminal 31 and terminal 30 through a circuitincluding the winding 44, conductor 43, contacts 39 and 40, andconductor 41. This will cause the armature 8 to be raised. As thearmature 8 moves upward the clutch 12 will engage the member 13 and theelectrode 18 will be moved toward the bar 4. At the same time the bar 4will be moved by the links 7 from the position shown in Fig. 1 to theposition shown in Fig. 3, where the point 5 of the puncturing device issubstantially in line of the axis of the member 2. As the puncturingdevice moves in line with the axis of the member 2 the upper end of theelectrode 18 is moved somewhat violently into contact with the tip ofthe puncturing device. hen the electrode 18 is formed out of titaniumcarbid, for instance, the body of the electrode is a fairly-goodconductor of electricity, regardless of its temperature. After such anelectrode has been used for some time in an arc-lamp, however, the tipof the electrode becomes covered with a layer or coating composedlargely of titanium oxid. This film or coating isa poor conductor ofelectricity when cold. At the same time a deposit composed largely oftitanium oxid is usually formed upon the portion of the upper electrodeof the lamp adjacent the are. This deposit is also a poor conductor ofelectricity, particularly when cold. \Vith many other materials fromwhich an electrode giving an efficient luminous arc may be formed thesame or similar tendencies to the formation of a film oreoating ofnon-conducting material on the electrode-tip or on adjacent objects, orboth, is experienced. With the use of the puncturing device 5, providedwith a sharpened edge or point 5 however, good contact will always beestablished between the body of the electrode 18 and the electrode 4, asthe engagement between the electrode 18 and the point 0 is such as toforce the metal of the contact-- the contact 40. This conductor includesa 1 point 5 into intimate engagement with the I3 body of the electrode18, regardless of any film or coating of poorly-conducting materialwhich may have been produced on either electrode 18 or thepuncturing-point 5. The downward movement of the electrode 18 is limitedby the engagement of the pawl 20 and the stop 22. After the arc isestablished in the manner hereinbefore described it is ordi narilymaintained until from the increase in arc length, caused by theconsumption of the electrode 18 or other cause, the potential voltage ofthe arc is increased beyond a predetermined amount. When this occurs,the winding of the potential coil 15 is energized sulficiently to movethe contact 19 into engagement with the contact 48. This throws alowresistance shun t, comprising the conductor 50, contact 49, contact48, and conductor 51, about the winding of the cut-out 3 1. Under theseconditions the contact 39 drops into engagement with the contact 40 andthe feeding operation of the lamp is repeated. The clutch 19 movesupward with the tubular member 13, by reason of the action of the spring23, until the pawl 20 engages the under side of the stop 21, after whichfurther upward movement of the member 13 takes place withoutcorresponding movement of the clutch 19. In each feeding operation ofthe lamp the member 13 is pulled through the yoke of the clutch 19 adistance equal to the amount consumed since the previous feedingoperation. hen the windings 1 1 are deenergized, the member 13 andelectrode 18 move downward a distance equal to the amount of play of thepawl 20 between the'stops 21 and 22. It will thus be seen that in theordinary operation of the lamp the arc struck after each feedingoperation is of constant length.

Instead of the form of puncturing device shown in Figs. 1 and 2 we mayuse the form shown in Fig. 4. In this form of our invention thepuncturing portion 5 is in the form of an elongated edge, as shown,rather than in the form of a conical point. This form of puncturingdevice facilitates the transfer of the upper end of the are from itsstartingplaee on the puncturing device 5' to the body of the bar 1 andlessens the time during which the arc extends from the device 5, thuslengthening the life of the puncturingdevice.

In the form of our invention shown in Fig. 2 the negative electrodes 60may be similar to the electrode 18, heretofore described; but it is notmoved in the feeding operation of the lamp. The positive electrode ofthe lamp, however, is different. It comprises a somewhat massive tubularshell member 61, formed of some material, such as wrought-copper, whichis a good conductor both of heat and electricity. A metallic bar 62 isslidingly mounted in the bore of the member 61. The lower end of the bar62 carries a detachable puncturing member 63, having a sharpened pointwhich is preferably formed of the same suitable material as the member5. The upper end of the bar 62 is provided with a shoulder 6 1. A washersurrounds the bar 62 above the upper end of the member 61 and below theshoulder 64:. The washer 65 is connected to the armature 66 of asolenoid 67, which is carried by the member 61 through a bracket 68. Aspring-pressed pawl 69 hooks over the upper end of the bar 62 and locksit to the member 61 when the lamp mechanism is in the condition shown inFig. 2. When the coil 67 is energized, however, the washer 65 movesupward and engages a cam-surface 70 of the pawl 69 to force it out ofengagement with the bar 62. The upward movement of the washer 65 iscontinued until the puncturing device 63 is moved from the exposedposition shown in full lines in Fig. 2 to position shown in dotted linesin Fig. 2. The member 61 passes through the opening in a washer-clutch75. One end of the washerclutch is connected to a U-shaped armature 76by a connecting-rod 7 7. A number of ratchet-teeth 78 are shown asformed on the bar 77. The pivoted armature 79, cooperating with anelectromagnet 80, is used to engage the teeth 78 and prevent downwardmovement of the connecting-rod 77 when the. electromagnet 80 isdeenergized. \Vhen the electromagnet 80 is operatively energized,however, the armature 79 is moved away from the position in which itengages the teeth 78. Conductors 81 and 82 supply current to the lamp. Aconductor 83 connects conductor 81 to the lower negative electrode 60 ofthe lamp. The conductor 83 may contain a suitable regulating resistance84. One terminal of the winding 85, which cooperates with the U-shapedarmature 7 6, is connected to the conductor 82. The other terminal ofthe winding 85 is connected to one terminal of the coil 67. The otherterminal of the coil 67 is connected to the tubular member 61 by aconductor 86. The member 61 and bar 62 are in good electrical contactthrough their physical engagement with each other. One terminal of theelectromagnet 80 is connected to the line 86 by conductor 87. The otherterminal of the electromagnet 80 is connected to the electrode 60 byconductor 88. The out of-service condition of this form of our inventionis that shown in Fig. 2. When the conductors 81 and 82 are connected toa suitable source, current will begin to flow through a circuit including conductor 83, conductor 88, winding of the electromagnet 80,conductor 87, coil67, and winding 85. This current will be suflicient tooperatively energize the coil 80, whereupon the armature 79 will beattracted and will release the bar 77. This will allow the member 61 andparts secured to it to move toward the electrode 60. The weight of theparts are such that the tip of the puncturing device 63 will engage theupper end of the electrode 60 with some violence. This will besufficient to puncture any film or layer of non-conducting materialwhich may cover the end of the electrode or the puncturing device andinsure good electrical contact between the bar 61 and electrode60. Assoon as contact is established between the electrodes 60 and bar 62current will begin to flow through a circuit comprising conductor 83,.

electrode 60, bar 62, member 61, conductor 86, coil 67, and winding 85.Passage of this current will be suflicient to opcratively energize thecoil 67 and winding 85. The coil 67 and parts moved thereby areconstructed to operate more rapidly than the winding 85 and partscomposed by it, in consequence of which the bar 62 is first drawn up inthe member 61, after which the member 61 is moved upward by the actionof the winding 85 of the armature 76. As the bar 62 is moved out of con-'tlietavith the electrode 60 an arc will be drawn between them whichwill be immediately transferred from the device 63 to the end of themember 61. To avoid any trouble from the cementing together of the bar69. and member 61 by material deposited on their lower ends from theare, the bore of the member 61 may be enlarged at the lower end, asshown.

It will be obvious to all those skilled in the art that many changes maybe made in the forms in which our invention is shown as embodied withoutdeparting from the spirit of our invention, and it is not intended thatthe claims hereinafter made shall be limited by the construction shownmore than is made necessary by the state of the art.

W'hat we claim as new, and desire to secure by Letters Patent of theUnited States, is

1. In an arclamp,an electrode, a second electrode, a film-puncturingdevice carried thereby,and means for causing said film-puncturing deviceto engage the first-mentioned electrode in the feeding operation of thelamp.

2. In an arc-lamp, a non -consuming electrode,a consumingelectrode,afilm-puncturing device carried by the non-consumingelectrode, means for causing said puncturing device to engage theconsuming electrode in the feeding operation of the lamp.and means formoving said film-puncturing device out of the arc path after an arc isstarted between the electrode.

3. In combination, an electrode the arcing end of which becomes coveredwith a non-conducting film or layer in the operation of the lamp, andmeans for puncturing the layer and starting an are from said electrode.

1. In an arc-lamp, a consuming electrode,a non-consuming electrode,apuncturing device carried thereby,and means for causing a somewhat-violent engagement between the consuming electrode and thepuncturing device.

5. In combination, a pair of cooperating electrodes,and means forpuncturing a film or coating of poorly-conducting material which mayhave been formed on one or both of said electrodes to facilitate thepassage of an are between said electrodes.

6. In an arc-lamp,a pair of co '3perating electrodes,and means forpuncturing a iilm or coating of poorly-eonducting material, which mayhave been formed on one or both of said electrodes, to facilitate thepassage of an are between said electrodes, said means comprising a sharpdevice carried by one of said electrodes, and mechanism for bringingabout a somewhat-violent engagement between said device and the other ofsaid electrodes.

In witness whereof we have hereunto set our hands this 6th day of July,1904-.

ALBERT G. DAVIS. JOHN E. HUBBELL. \Vitnesses:

BENJAMIN B. HULL, HELEN On'rom').

